From 0b3291d658497157fa3ec2e2ceb7e5d700011561 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Mon, 29 Jun 2026 23:30:13 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Bolt:=20Replace=20blocking=20time.s?=
 =?UTF-8?q?leep=20with=20asyncio.sleep=20in=20get=5Fframe=5Fimage?=
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Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: benpiper <4343814+benpiper@users.noreply.github.com>
---
 .jules/bolt.md  | 4 ++++
 backend/main.py | 5 +++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/.jules/bolt.md b/.jules/bolt.md
index e6d39e6..cc78a19 100644
--- a/.jules/bolt.md
+++ b/.jules/bolt.md
@@ -16,3 +16,7 @@
 ## 2024-06-28 - Optimize array lookups in high-frequency React event handlers
 **Learning:** Even if data is pre-processed/memoized (like cached `parsedTimestamps`), performing an O(N) linear search on that array inside a high-frequency event handler (like `<video onTimeUpdate>`, which fires multiple times per second) can cause UI stuttering for large arrays.
 **Action:** When searching sorted arrays (like ordered video timestamps) in high-frequency event loops, replace linear iteration loops with an O(log N) binary search to minimize main thread blocking and ensure smooth UI execution.
+
+## 2024-05-24 - Replace blocking time.sleep with asyncio.sleep in async FastAPI routes
+**Learning:** FastAPI async routes must not use blocking I/O calls like `time.sleep()`. This completely blocks the main event loop, causing the entire application to hang and fail to process other concurrent requests.
+**Action:** Always use `await asyncio.sleep()` in `async def` route handlers when waiting or polling, so the event loop can process other tasks.
diff --git a/backend/main.py b/backend/main.py
index f637f4a..1db6da0 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -12,7 +12,6 @@
 from typing import List, Dict, Any
 from pydantic import BaseModel, Field
 from pathlib import Path
-import time
 
 from scanner import scan_directory_for_videos
 from extractor import async_extract_keyframes_parallel, async_get_video_duration
@@ -858,8 +857,10 @@ async def get_frame_image(directory_path: str, frame_index: int, project: Projec
 
     max_wait = 30
     waited = 0
+    # ⚡ Bolt: Use asyncio.sleep instead of time.sleep to avoid blocking the main event loop
+    # Impact: Allows server to handle concurrent requests while polling for frame creation
     while not file_path.exists() and waited < max_wait:
-        time.sleep(1)
+        await asyncio.sleep(1)
         waited += 1
 
     if file_path.exists():